Two studies are proposed to investigate children's understanding of and behavior toward stimuli which differ in craniofacial maturity. In Study 1, 80 3-year-old and 80 5-year-old children will be asked to select from pairs of novel stimuli the 'cuddly' one. An adult sample will also perform this task. The stimuli will exhibit either a babyish or a mature facial configuration, and will be constructed from either a soft or a hard substance, producing a soft babyfaced, a hard babyfaced, a soft maturefaced, and a hard maturefaced stimulus. The results of Study I will reveal (a) the developmental course of the ability to categorize babyfaced and maturefaced stimuli on the basis of the activities which they afford; (b) the development of the ability to categorize hard and soft objects on this basis; and (c) the relative impact of facial configuration and object substance on these perceptions. The same 3- and 5-year-old children will participate in Study 2. In this study, subjects will be invited to play with one of the four versions of stimuli described in Study 1. Children's spontaneous behavior toward the stimuli will be assessed. In particular, behaviors will be coded into categories including giving affection to the stimulus (e.g., hugging, kissing), providing nurturance to the stimulus (e.g., feeding, rocking), activities which imply physical strength on the part of the stimulus (e.g., having it fly, or climb), and having the stimulus toy perform activities which indicate responsibility (e.g., driving a car). These data will reveal (a) the impact of facial configuration on children's behaviors toward the stimuli; (b) the impact of object substance on children's behaviors; and (c) the relative impact of these two stimulus dimensions on behavior. Finally, a comparison of the results of Study 1 and 2 will yield information about the relationship between the development of children's perceptions of and behavior toward stimuli which vary in facial configuration and substance.